This paper records the spatial and temporal distribution of deep-sea benthic microfossils (Foraminifera, single-celled organisms) from the latest Oligocene to earliest Pliocene (about 28 to 4 million years ago) from Ocean Drilling Program cores in the southern Indian Ocean. Key taxa are illustrated and their stratigraphic distribution is presented as they respond to a period of marked global climatic changes, with a pronounced warm period in the mid-Miocene followed by subsequent cooling.